———————————————————————————This file constitutes revision 0 of the release notes for LS-DYNA version R10.0.0———————————————————————————

I. LICENSE

The string “REVISION 10” must appear in the LS-DYNA license file in order to run version R10.0.0. Please contact your LS-DYNA distributor (keys@lstc.com ifyou’re a direct customer of LSTC) if you need to have your license updated.

Due to missing ANSYS libraries, R10.0.0 cannot be run on Windows machines using an ANSYS-issued license, nor can ANSYS data format be output by LS-DYNA.

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II. DOCUMENTATION

Until such time the R10.0 User’s Manual is posted at www.lstc.com/download/manuals, the DRAFT User’s Manual at www.lstc.com/download/manuals may be used as a temporary substitute, but please be aware that a few features in the DRAFTUser’s Manual are not implemented in version R10.0.0.

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III. NOTES

The remainder of this file provides a brief description of new features andenhancements in version 10.0.0. Some bug fixes are also described, some of which may also be included in R9 releases.

The items are arranged by category. Understand that in many cases,a particular item could fall under more than one category, but in theinterest of brevity, each item is listed only once, under a single category.

Excluding the “Miscellaneous” category, the categories are arranged alphabetically.

Enhance the robustness of *AIRBAG_INTERACTION to help avoid instabilityin MPP when the interaction involves more than two bags.

*AIRBAG_PARTICLE:– Adjust dm_out calculation of vent hole to avoid truncation error.– Fix bug in chamber output when there are multiple airbags and multiple chambers not in sequential order.– Bug fix for closed volume of airbag/chamber with intersecting tubes.– Add new feature to allow user to define local coordinates of jetting of particles through internal vents.– Support *SENSOR_CONTROL for CPM airbag.– CPM is not supported for dynamic relaxation. Disable CPM airbag feature during DR and reactivate airbag following DR.– Allow solid parts in definition of internal part set. The solid volume will be excluded from the the airbag volume.– Allow additional internal part set for shells. The shell part should form a closed volume and its volume will be excluded from the airbag volume.

*CONTROL_ALE, *CONSTRAINED_LAGRANGE_IN_SOLID and *ALE_REFERENCE_SYSTEM:If NBKT<0 in *CONTROL_ALE, call *DEFINE_CURVE to load a curve defining the numberof cycles between bucket sorting in function of time.If NBKT>0, the bucket sorting is activated if the mesh rotations and deformationsare large.

*ALE_FSI_TO_LOAD_NODE: Implement a mapping of the FSI accelerations(penalty forces/masses) computed by *CONSTRAINED_LAGRANGE_IN_SOLID (ctype=4)between different meshes.

*DATABASE_FSI, *DATABASE_BINARY_FSIFOR and *DATABASE_BINARY_FSILNK:Add a parameter CID to output fsi forces in a local coordinate system.

*DATABASE_ALE: Add VAR=15 to output the kinetic energy by elements and ALE groups.

*BOUNDARY_PWP can now accept a *DEFINE_FUNCTION instead of a load curve.The input arguments are the same as for *LOAD_SEGMENT: (time, x, y, z, x0,y0, z0).

Add option of “toffset” for *BOUNDARY_PRESCRIBED_ORIENTATION_RIGID to offsetthe curves by the birth time.

MPP now supports MCOL coupling, *BOUNDARY_MCOL.

Fix bug of there being fully constrained motion of a rigid part when prescribingmore than one translational dof with *BOUNDARY_PRESCRIBED_MOTION_RIGID whilecon2=7 in *MAT_RIGID, i.e., all rotational dof are constrained.

Instead of error terminating with warning message, STR+1371, when *BOUNDARY_PRESCRIBED_MOTIONand *BOUNDARY_SPC is applied to same node and dof, issue warning message, KEY+1106, andrelease the conflicting SPC.

Fix erroneous results if SET_BOX option is used for *BOUNDARY_PRESCRIBED_MOTION.

Fix *BOUNDARY_PRESCRIBED_ACCELEROMETER_RIGID for MPP. It may error terminateor give wrong results if more than one of this keyword is used.

Added instruction *BOUNDARY_ACOUSTIC_IMPEDANCE for explicit calculationsthat applies an impedance boundary condition to the boundary of*MAT_ACOUSTIC element faces. This is a generalization of the non-reflectingboundary conditon. Both *LOAD and *BOUNDARY_ACOUSTIC_IMPEDANCE maybe used on the same faces, in which case the boundary acts like bothand entrant and exit boundary.

Fix the single precision version so that *INCLUDE_UNITCELL now has no problemto identify pairs of nodes in periodic boundaries.

When using *INCLUDE_UNITCELL to generate Periodic Boundary Constraints (PBC)for an existing mesh, a new include file with PBCs is generated instead ofchanging the original mesh input file. For example, if users include a filenamed “mesh.k” through *INCLUDE_UNITCELL (INPT=0), a new include file named“uc_mesh.k” is generated where all PBCs are defined automatically followingthe original model information in mesh.k.

*INCLUDE_UNITCELL now supports long input format in defining the element IDs.

Include SPC boundary conditions as part of H8TOH20 solid element conversion.

Add a new option SET_LINE to *BOUNDARY_PRESCRIBED_MOTION:This option allows a node set to be generated including existing nodes and newnodes created from h-adaptive mesh refinement along the straight line connecting twospecified nodes to be included in prescribed boundary conditions.

________________________ Blast ___________________

*PARTICLE_BLAST and DES:– Consider eroding of shell and solid in particle_blast.– Support interface force file output for gas particle-structure coupling.– Bug fix for wet DES coupled with beam.– Support *SET_NODE_GENERAL PART with SPH or DES.– MPP now uses async communication for DES coupling to improve general performance.– Support for solid element whens modeling irregular shaped charge with HECTYPE=0/1 in *PARTICLE_BLAST.– Output adaptive generated DES and NODE to a keyword file.

Fix inadvertent detonataion of HE part when there are more than one HE part andeven though the HE part is not defined with *INITIAL_DETONATION.

Fixed explicit *BOUNDARY_USA_COUPLING to support *INITIAL_STRESS and*INITIAL_STRAIN_ usage, typically from a dynain file.

Fixed explicit *BOUNDARY_USA_COUPLING to support *CONTROL_DYNAMIC_RELAXATIONIDRFLF=5, so a static implicit calculation can be used to initialize/preloada model before conducting an explicit transient calcultion. If inertiarelief is used during the static phase, then it must be disabled with*CONTROL_IMPLICIT_INERTIA_RELIEF for the explilcit phase.

For *PARTICLE_BLAST, when coupling with DEM, the DEM nodes that areinside HE domain are automatically deactivated.

Add support for solid elements when modeling irregular shaped charge withHECTYPE=0/1 for *PARTICLE_BLAST.The original approach only supports shell elements and the initial coordinatesof HE particle are at shell surface. The model had to relax severalhundred timestep to let particle fill in the interior space, which was not convenient.Using new approach, the initial positions of HE particles are randomly distributedinside the container by using solid element geometry.Both hex and Tet solids are supported.

The flow field calculation will be skipped if the structural time-step ismuch smaller than the fluid time step, until both time-steps reach the sameorder. This will save CPU time in some fluid/structure interaction (FSI)problem calculations.

In addition to depending upon the local CFL number, the fluid time step‘dt’ calculation has been modified to also adjust dynamically to extremeflow conditions. This makes stiff flow problems more stable especially in3D fluid problem calculations when the mesh quality is poor.

Moving mesh solvers:====================

Corrected several aspects of the implicit ball-vertex (BV) mesh motion solverfor the following keywords:*ICFD_CONTROL_MESH_MOV*CESE_CONTROL_MESH_MOV

The absolute tolerance argument is no longer used by the BV solver. As anexample, the following is all that is needed for CESE moving mesh problems:*CESE_CONTROL_MESH_MOV $ ialg numiter reltol 1 500 1.0e-4

Added real 2D CESE output, and this is confirmed to work with LSPP4.3and later versions. This also works for d3plot output with the 2D CESEaxisymmetric solver.

For all immersed-boundary CESE solvers, corrected the plotting of theSchlieren number and the chemical species mass fractions.

The following new CESE input cards are related to surface d3plot output:*CESE_SURFACE_MECHSSID_D3PLOT*CESE_SURFACE_MECHVARS_D3PLOTIn conjunction with the above, new FSI and conjugate heat transferoutput on solid (volume) mesh outside boundaries is now supported.

*CESE_FSI_EXCLUDE is a new keyword for use with the CESE immersed boundarymethod FSI solvers. With it, unnecessary structural parts that are notactively participating in the FSI in the CESE IBM-FSI solver can now beexcluded from the CESE FSI calculation. This is also supported for thecase when some of the mechanics parts involve element erosion.

CESE chemistry solvers:=======================

In R10, we also updated several things in the FSI solver with chemistry called FSIC.In chemical reacting flow, a delta time between iterations is extremely important forcode stabilization and thus, to get reasonable results. To this end, we optimized suchan iterative delta time, which is based on the CFL number. This optimization is based onthe gradient of the local pressure, which we think will dominate control of the CFL number.

Next, the total number of species are increased up to 60 species in chemical reacting flow,so that the reduced Ethylene(24~53 species) and Methane(20~60 species) combustion arepossible with this version.

We will update more practical examples about FSIC problems including precise experimentalvalidations.

Note that we can provide some related examples upon user request.

Other corrections of note include the following:

Brought in enthalpy-related corrections to the CESE chemistry solvers.

Enabled output of the timing information for the CESE chemistry solvers.

Added restart capability to the CESE chemistry solvers.

________________________ *CHEMISTRY ___________________

New inflator models of Pyrotechnic and Hybrid type are updated. It isimportant to note that these are basically 0-dimensional models via thefollowing two main keywords,

*CHEMISTRY CONTROL_INFLATOR*CHEMISTRY_INFLATOR_PROPERTIES

By using the *CHEMISTRY CONTROL_INFLATOR keyword, the user can select thetype of of the solver, output mode, running time, delta t, and timeinterval for output of time history data.

For example, if we have a keyword set up as,*CHEMISTRY CONTROL_INFLATOR, $ isolver ioutput runtime delt p_time 1 0 0.1 1.0e-6 5.0e-4

with “isolver set to 1”, the user can simulate a conventional Pyrotechnicinflator mode, while with “isolver” set to 2 or 3, Hybrid inflator simulationis possible.

In addition, to continue an airbag simulation via an ALE or CPM method,the user can save the corresponding input data file by using “ioutput” option.For more details about airbag simulations using a saved data file, refer tothe keyword manual.

Also, note that the updated version has two options for the Hybrid models:– isolver = 2 => Hybrid model for the cold flow– isolver = 3 => Hybrid model for the heated flow.

In the *CHEMISTRY_INFLATOR_PROPERTIES keword, there are several cards to set upthe required properties of an inflator model. The first two cards are for thepropellant properties involved in inflator combustion.For example, $card1: propellants $ comp_id p_dia p_height p_mass p_tmass 10 0.003 0.0013 2.0e-5 5.425e-3 $card2: control parameters $ t_flame pindex A0 trise rconst 2473. 0.4 4.45e-5 0.0 0.037In the first card, the user can specifiy the total amount of propellant particlesand their shape.Using the second card, the user can also specifiy the thermodynamics of the propellantand its burning rate.To support the options in card2, especially the second option, pindex, and the third, A0,we provide a standalone program upon request for the propellant equilibrium simulation.The remaining cards are for the combustion chamber, gas chamber, and airbag, respectively.

________________________ CONTACT ___________________

*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_MORTAR_TIED_WELD for modeling welding has been added.Surfaces are tied based on meeting temperature and proximity criteria.Non-MORTAR version of this contact was introduced at R9.0.1.

Change “Interface Pressure” report in intfor filefrom abs(force/area) to -force/area, which gives theproper sign in case of a tied interface in tension.

Rework input processing so that more than one *CONTACT_INTERIOR may be used,and there can be multiple part sets in each one.

Minor change to how pressure is computed for triangles in the intfor database.

Fix 2 bugs for contact involving high order shell elements:– When high order shell elements are generated by SHL4_TO_SHL8.– When using a large part id like 100000001.

Implement a split-pinball based contact option for neighbor elements insegment-based contact. Invoke this option by setting |SFNBR|>=1000.The new algorithm is more compatible with DEPTH=45 so that thereis no longer a need to split quads.

The effect of shell reference system offsets on contact surface location is now properlyconsidered when running MPP. The shell offset may be specified using NLOC in *SECTION_SHELLor in *PART_COMPOSITE, or by using the OFFSET option of *ELEMENT_SHELL.This effect on contact is only considered when CNTCO is set to 1 or 2 in *CONTROL_SHELL.

Fix bug of zero forces in rcforc at time=0.0 for *CONTACT_AUTOMATIC_SURFACE_TO_SURFACEafter dynamic relaxation when consistency is on in SMP.

Fix input error when using many *RIGIDWALL_GEOMETRIC_… with _DISPLAY option.

Fix input error when *CONTACT_ENTITY is attached to a beam part, PID.

Fix error termination due to negative volume, SOL+509, even when*CONTACT_ERODING… is set. This affects MPP only.

Check whether a slave/master node belongs to a shell before updating thenodal thickness when ISTUPD>0.0 in *CONTROL_SHELL and SST/MST.ne.0.0 andin SSFT/SMFT=0.0 card 3 of *CONTACT_….. For SMP only.

Fix penetrating nodes when using *CONTACT_ERODING_NODES_TO_SURFACE with SOFT=1in *MAT_142/*MAT_

Fix seg fault when using *CONTACT_AUTOMATIC_SINGLE_SURFACE_TIED with consistencymode, .i.e. ncpu<0, for SMP.

Fix spurious repositioning of nodes when using *CONTACT_SURFACE_TO_SURFACE for SMP.

Added support to segment based contact for the SRNDE parameter on optional card E.This option allows round edge extensions that do not extend beyond shell edges andalso square edges. The latter overlaps with the SHLEDG parameter on card D.

Fixed a potential memory error that could occur during segment based contact input.

Fixed an error that could cause an MPP job to hang in phase 3. The errorcould occur when SOFT=2 contact is used with the periodic intersection checkand process 0 does not participate in the contact.

Modified SOFT=2 contact friction when used with *PART_CONTACT to definefriction coefficients, and the two parts in contact have different coefficientvalues. With this change, the mu values used for contact will be the average of thevalues that are calculated for each part. Prior to this change, mu wascalculated for only the part that is judged to be the master. This change makesthe behavior more predictable and also makes it behave like the other contactswith SOFT=0 and SOFT=1.

Added a warning message (STR+1392) for when trying to use the ORTHO_FRICTION contact option withSOFT=2 contact, because that option is not available. The contact type is switched to SOFT=1.

Fixed serious error in MPP *CONTACT_2D_AUTOMATIC_SURFACE_TO_SURFACE when usedwith node sets to define the contact surfaces. The master side was likely totrigger an spurious error about missing nodes that terminated the job.

Swiched segment based (SOFT=2) non-eroding contact to prevent it from adding anynew segments when brick element faces are exposed when other elements are deleted.There were two problems. The first is that the interface force file could notsupport NFAIL=1 on *DATABASE_EXTENT_INTFOR because the intfor file does not expectnew segments to replace the old, so it just undeletes the old segments instead ofadding the new. The second problem is that when non-eroding contact is used, weonly have enough memory in fixed length arrays for the segments that exist att=0. When segments are deleted, I was using the space that they vacated to createnew segments, but it was very likely that some segments could not be created whenthe number of open spaces was less than the number of new segments that are needed.In this case, some segments would not be created and there would be surfaces thatcould be penetrated with no resistance. This behavior is impossible to predict, soit seems better to prevent any new segments from being created unless erodingcontact is used.

Fixed a segment based contact error in checking airbag segments. This affectsonly airbags that are defined by control volumes, that is defined by *AIRBAG.The symptom was a segmentation fault.

Fixed SMP eroding segment based (SOFT=2) contact which was not activating the negativevolume checking of brick elements. The MPP contact and the other SMP contacts weredoing this but not SMP SOFT=2.

Fixed support for CNTCO on *CONTROL_SHELL by segment based (SOFT=2) contact. Itwas adjusting the contact surface only half of what it should have done.

Fixed eroding segment based contact when used with the CNTCO>0 on *CONTROL_CONTACT.A segmentation fault was occurring.

Modified MPP segment based (soft=2) contact to use R8 buffers to passnodal coordinates. This should reduce MPP scatter when decompositionchanges.

Added support for using a box to limit the contact segments to those initially inthe box when using eroding segment based contact. The box option has not been availablefor any eroding contact up until now. (SOFT=2 and SBOXID, MBOXID on *CONTACT_ERODING_…).

Fixed force transducers with MPP segment based contact when segments are involvedwith multiple, 2-surface force transducers. The symptom was that some forces weremissed for contact between segments on different partitions.

Added support for *ELEMENT_SOURCE_SINK used with segment based contact. With this update,inactive elements are no longer checked for contact.

Fixed an MPP problem in segment based contact that cased a divide by zeroduring the bucket sort. During an iteration of the bucket sort, allactive segments were somehow in one plane which was far from the originsuch that a dimension rounded to zero. The fix for this should effectonly this rare case and have no affect on most models.

Modified segment based (SOFT=2) contact to make SMP and hybrid faster,particularly for larger numbers of processors.

Fixed thermal MPP segment based contact. The message passing of thermal energy dueto friction was being skipped unless peak force data was written to the intfor file.

Support the VC parameter (coefficent for viscous friction) in the case ofsegment based contact, which has previously been unsupported. This option will work bestwith FNLSCL>0, DNLSCL=0 on optional card D. The card D option causes the contactforce to be proportional to the overlap area which causes even pressure distribution.

Enabled segment based contact (SMP and MPP) to work with type 24 (27-node) brick elements.

Fixed MPP segment based contact for implicit solutions. During a line search,some data was not restored correctly when the solver goes back to the last convergedstate. This caused possible memory errors.

Fixed friction for MPP segment based contact in the implicit solver. The sliding velocity wascalculated incorrectly using the explicit time step rather than the implicit step.

Fixed a bug in MPP *CONTACT_2D_AUTOMATIC…, where a flaw in code used duringMPP initialization could cause segments to fail to detect penetration.

Fixed the thick beam checking of *CONTACT_2D_AUTOMATIC_SINGLE_SURFACE in the MPP version.There was a memory error that could occur if thick beams were in the model.

PENMAX and SLDTHK has taken over the meanings of SST and TKSLSin R9 and earlier, although in a different way. NowPENMAX corresponds to the maximum penetration depth for solidelements (if nonzero, otherwise it is a characteristic length).SLDTHK is used to offset the contact surface from the physicalsurface of the solid element, instead of playing with SST andTKSLS, which was rather awkward. This update also saves thepain of having to treat shells and solids in separate interfacesif these features are wanted. This changes the behavior in someinputs that did have SST turned on for solids, but a necessarymeasure to make the contact decent for future versions.

The characteristic length for solid elements has been revised to notresult in too small sizes that would lead to high contact stiffnessesand less margin for maximum penetration.

SFS on CONTACT_…_MORTAR can be input as negative, thencontact pressure is the -SFS load curve value vs penetration.

Smooth roundoffs of sharp edges in MORTAR contact has been extendedto high order segments, meaning that edge contact is valid even in thiscase.

The MORTAR contact now honors the NLOC parameter for shells, see *SECTION_SHELL,adjusting the contact geometry accordingly. Note that CNTCO on *CONTROL_SHELLapplies as if always active, meaning that if NLOC is on, then CNTCO will alsobe “on” for MORTAR contacts.

Output of contact gaps to the intfor file is now supported for MORTAR contact, see*DATABASE_EXTENT_INTFOR.

Transducer contacts, *CONTACT_…_FORCE_TRANSDUCER, are supportedfor MORTAR contact in SMP and MPP. A disclaimer is that the slave and master setsin the transducer have to be defined through parts or part sets.Warnings are issued if this is violated.

Option 2 is now supported for tiebreak MORTAR contact, *CONTACT_…_MORTAR_TIEBREAK,but only for small sliding. Options 4 and 7 are supported in the MORTAR tiebreakcontact for any type of sliding.

For explicit analysis, the bucket sort frequency for MORTAR contact is 100, butcan be changed through parameter BSORT on the CONTACT_…_MORTAR card orNSBCS on CONTROL_CONTACT. Note that the MPP bucket sort parameter does not apply.This assumes to improve the efficiency of MORTAR explicit contact significantlycompared to R9 and earlier versions.

Dynamic friction is supported in MORTAR contact for explicit and implicit dynamicanalysis. See FD and DC on *CONTACT_… card.

Wear calculations are supported for the MORTAR contact. See CONTACT_ADD_WEAR.

Triangular shell form 24 is supported with MORTAR forming contact and accountsfor high order shape functions.

Automatic MORTAR contact now supports contact with end faces ofbeam elements and not just the lateral surfaces.

Mortar contact is available in 2D plane strain andaxisymmetric simulations, but only for SMP implicit. See CONTACT_2D_…MORTAR.

Wear computed from *CONTACT_ADD_WEAR can optionally be output to dynainon optional card of *INTERFACE_SPRINGBACK_LSDYNA. This will generate*INITIAL_CONTACT_WEAR cards for subsequent wear simulations, and LS-DYNAwill apply this wear and modify geometry accordingly. Restrictionsas described in the manual apply.

Improve SOFT=6 under *CONTACT_FORMING_ONE_WAY_SURFACE_TO_SURFACE to allow usersto define part ID and a node set is automatically generated.

________________________ *CONSTRAINED ___________________

Add frictional energy calculation for constraint-based rigid walls.

*CONSTRAINED_BEAM_IN_SOLID:– Works with r-adaptivity now.– Can now constrain beams in tshells as well as solids.

The following options do not support MEMORY=auto properly. The MEMORY=auto option willbe turned off in this section and report an error if additional memory allocation is needed.*CONSTRAINED_LINEAR_OPTION*CONSTRAINED_MULTIPLE_GLOBAL

Switched translational joints with stiffness to use double precision storagefor the displacement value so that the calculated forces are more accurate.This prevents round-off error that can become significant.

Fixed *CONSTRAINED TIED_NODES_FAILURE when used with MPP single surfacesegment based contact. Non-physical contact between segments that sharetied constraints was being penalized leading to failure of the constraints.

The SPR models (*CONSTRAINED_SPR2, *CONSTRAINED_INTERPOLATION_SPOTWELD)now support the SPOTDEL option of *CONTROL_CONTACT. That means if shellelements involved in the SPR domain fail, the SPR gets deactivated.

________________________ *CONTROL ___________________

Fix possible error termination with single precision MPP when PSFAIL.ne.0 in*CONTROL_SOLID and using solid formulation 10/13/44.

Fix spurious deletion of elements when using TSMIN.ne.0.0 in *CONTROL_TERMINATION,erode=1 in *CONTROL_TIMESTEP and initialized implicitly in dynamic relaxation.

Added keyword *CONTROL_ACOUSTIC to calculate the nodal motions of*MAT_ACOUSTIC nodes for use in d3plot and time history files. Withoutthis option the *MAT_ACOUSTIC mesh propagates pressure but does notdeform because it uses a linear Eulerian solution method. The structuralresponse is unaffected by this caluclation; it is only for visualizationand will roughly double the time spent computing acoustic elementresponse.

When IACC=1 on *CONTROL_ACCURACY and for shell type 16/-16 in nonlinear implicit,shell thickness change due to membrane strain when ISTUPD>0 in *CONTROL_SHELLis now included in the solution process and will render continuity in forcesbetween implicit time steps. The output contact forces will reflect theequilibriated state rather than the state prior or after the thickness update.

Fix bug when RBSMS in *CONTROL_RIGID, affecting mass scaled solutions,is used in conjunction with *ELEMENT_INERTIA and/or *PART_INERTIA,specifically with choices of IFLAG on*CONSTRAINED_RIGID_BODIES and *CONSTRAINED_EXTRA_NODES.

Tshells added to the subcycling scheme (*CONTROL_SUBCYCLE).

Tshells and spotweld beams are supported in selective mass scaling..See IMSCL in *CONTROL_TIMESTEP.

Add a new keyword: *CONTROL_FORMING_SHELL_TO_TSHELL to convert shell elementsto tshell elements.– If a parent node has SPCs, the same SPC constraints will be applied to the corresponding tshell nodes.– If adaptivity is invoked, *BOUNDARY_SPC_SET is automatically updated to include newly generated nodes.– Allows the normal of the segment set to be changed.– Can offset the generated tshells from the mid-surface of the parent shells.– Automatically generate segment sets for the top and bottom surfaces, which can be used for contact.

________________________ Discrete Element Method ___________________

Implement generalized law of erosion for *DEFINE_DE_TO_SURFACE_COUPLING basedon the following article in the journal “Wear”:Magnee, A., Generalized law of erosion: application to various alloysand intermetallics, Wear, Vol. 181, 500, 1995.

Fixed bug affecting output from beam elements ELFORM=2 when certain uncommon inputsare present. Forces and moments in the output files could be wronglyrotated about the beam axis. This affected the output files only, notthe solution inside LS-DYNA. The error could occur under two circumstances:(a) if IST on *SECTION_BEAM is non-zero, the output forcesand moments are supposed to be rotated into the beam’s principal axissystem, but this rotation could be applied to the wrong beam elements;and (b) when no ELFORM=2 elements have IST, but the model also containsbeams with ELFORM=6 and RRCON=1 on the SECTION_BEAM card, some of theELFORM=2 elements can have their output forces and moments rotated by1 radian.

Fix a bug for 2d seatbelt that could occur when a model has both 1d and 2d belts,and a 1d pretensioner of type 2, 3 or 9.

Fix an MPP seatbelt bug that could occur when using a type 9 pretensioner.

Allows shell formulation 9 to be used for 2d seatbelt. It was reset to formulation 5 byLS-DYNA, no matter what formulation was input. Now, only formulation 5 and 9 areaccepted as input. Other formulations will incur error message.

MPP now supports *ELEMENT_MASS_MATRIX_NODE_(SET).

Added cohesive shell formulation -29. This formulation uses a cohesivemidlayer where local direction q1 coincides with the average of thesurrounding shell normals. This formulation is better suited forsimulating normal shear.

Fix incorrect load curve used if large value is used for FC<0 and/or FCS<0 in*ELEMENT_SEATBELT_SLIPRING.

Fix incorrect velocity on accelerometer if– velocity is prescribed on the rigid body that the accelerometer is attached to, and– INTOPT=1 in *ELEMENT_SEATBELT_ACCELEROMETER, and– *INITIAL_VELOCITY_GENERATION_START_TIME is used.

Fix incorrect discrete spring behavior when used with adaptivity.

Fix input error when using *DEFINE_ELEMENT_DEATH with BOXID>0 for MPP.

Modify tolerances on error messages SOL+865 and SOL+866 to prevent unnecessary errorterminations when translational or rotational mass of a discrete beam wasclose to zero.

Made the solid element negative volume warning SOL+630 for penta formulatgion 15consistent with the volume calculation in the element. With this change, elementsare deleted rather than the job terminating with error SOL+509.

Fixed the default hourglass control for shell form 16. It was defaultingto type 5 hourglass control rather than 8.

Fixed default hourglass control when the *HOURGLASS control card is used but no HGtype is specified. We were setting to type 1 instead of 2. Also, fixed thedefault HG types to match the user’s manual for implicit and explicit.

Fixed the fully integrated membrane element (shell ELFORM=9) when used with NFAIL4=1on *CONTROL_SHELL and there are triangular elements in the mesh. Triangular elementswere being deleted by the distorted element check.

Fixed a divide by zero error that occurred with *SECTION_BEAM, ELFORM=6,SCOOR=12 or -12, and node 3 was omitted on *ELEMENT_BEAM, and nodes 1 and 2are along the global y-direction or z-direction.

Fixed laminated shell theory for type 6 and 7 shell elements when madeactive by LAMSHT=3 or 5 on *CONTROL_SHELL.

Added an int.pt. variable for *PART_COMPOSITE_LONG and *PART_COMPOSITE_TSHELL_LONGcalled SHRFAC which is a scale factor for the out-of-plane shear stress thatallows the user to choose the stress distribution through thickness.This was motivated by test data that shows that for large differences is layershear stiffness, the parabolic assumpion is poor.

Fixed implicit hourglass stiffness in viscoelastic materials when used withtshell forms 5 or 6. The stiffness was much too small.

Modified tshell type 5 to use the tangent stiffness for calculating the Poisson’s affectsand hourglass control for *MAT_024. This makes the behavior softer during bucklingwhich is much more realistic.

Fixed a significant bug in segment based contact when SHLEDG=1 and SBOPT=3 or 5 andDEPTH<45, and shell segments in contact have different thicknesses. A penetrationcheck was using incorrrect thicknesses causing contact to be detected too late,particularly for edge to surface contact.

Improved the time step calculation for triangular tshell elements. The timestep was too conservative for elements with significant thickness. This fix doesnot affect tshell type 7.

Fixed all tshells to work with anisotropic thermal strains which can be definedby *MAT_ADD_THERMAL. Also, this now works by layer for layered composites.

Enabled tshell form 5 to recalculate shear stiffness scale factors whenplasticity material models 3, 18, 24, 123, or 165 are included in a composite section.Prior to this change the scale factors were based on elastic properties soafter yielding, the stress distribution was not what was expected. Thisnew capability supports the constant stress option, the parabolic option, andthe SHRFAC option on *PART_COMPOSITE_TSHELL_LONG.

Improved tshell 5 when used with mixed materials in the layers. A failure to usethe correct Poisson’s ratio was causing a less accurate stress tensor.

Modified the time step calcualtion for tshell forms 3 and 5. A dependence onvolumetric strain rate was removed in order to prevent oscillations in the time step whichcaused stability problems, particularly for tshell 5.

Fixed tshell constant shear stress option (TSHEAR=1 on *SECTION_TSELL or *PART_COMPOSITE).It was producing a not very constant stress distribution.

Fixed stress and strain output of tshells when the composite material flagCMPFLG is set on *DATABASE_EXTENT_BINARY. The transformation was backwards.

Fixed mass of parts reported to d3hsp when *ELEMENT_SHELL_SOURCE_SINKis used. The mass of inactive elements was being included.

Enabled *MAT_026 and *MAT_126 (HONEYCOMB) to be used with tshell forms3, 5, and 7. It was initialized incorrectly causing a zero stress.

Added a missing internal energy calculation for tshell form 6.

Enabled tshell forms 1, 2, and 6 to work with material types 54, 55, and 56.

Modified the z-strain distribution in tshell forms 5 and 6 when used incomposites with mixed materials that are isotropic. The existing assumed strain schemewas doing a poor job of creating a constant z-stress through the thickness.

Increased the explicit solution time step for thin shell composite elements.The existing method calculated a sound speed using the stiffness from thestiffest layer and dividing it by the average density of all layers. Thiscould be overly conservative for composites with soft layers of low density.The new method uses the average stiffness divided by average density. Thisis still conservative, but less so.

Corrected rotational inertia of thin shells when layers have mixed density and the outerlayers are more dense than innner layers. The fix will mostly effect elements that arevery thick relative to edge length.

Added support for *ELEMENT_SHELL_SOURCE_SINK to type 2 shells with BWC=1 on*CONTROL_SHELL.

Fixed *LOAD_STEADY_STATE_ROLLING when used with shell form 2 and Belytschko-Wong-Chang warping stiffness (BWC=1 *CONTROL_SHELL). The load was not being applied.

Improved the brick element volume calculation that is used by the option erodeelements (ERODE=1 on *CONTROL_TIMESTEP or PSFAIL.ne.0 on *CONTROL_SOLID). It wasnot consistent with the element calculation which caused an error termination.

Fixed all tshell forms to work with anisotropic thermal strains which can be definedby *MAT_ADD_THERMAL. Also, this now works by layer for layered composites.

Reworked shell output so that we can correctly output stress in triangular shells whentriangle sorting is active, that is when ESORT=1 or 2 on *CONTROL_SHELL.

*ELEMENT_T/SHELL_COMPOSITE(_LONG) and *PART_COMPOSITE_T/SHELL_(LONG):Permit the definition of zero thickness layers in the stacking sequence.This allows the number of integration points to remain constant even asthe number of physical plies varies and eases post-processing since aparticular integration point corresponds to a physical ply.Such a capability is important when plies are not continuous across acomposite structure.To represent a missing ply, set THK to 0.0 for the corresponding integrationpoint and additionally, either set MID=-1 or set PLYID to any nonzero value.Obviously, the PLYID option applies only to the keywords containing LONG.

Implemented sum factorization for 27-node quadratic solid that may increasespeed by a factor of 2 or 3.

Support second order solid elements (formulations 23,24,25,26) for*SET_NODE_GENERAL.

Modify initialization of material directions for solid elements.If there are only zeros for all the 6 values in *INITIAL_STRESS_SOLID,then the values from the other input (e.g. *ELEMENT_SOLID_ORTHO) are kept.

Enable *PART_STACKED_ELEMENTS to pile up shell element layers.Before, it was necessary that solid element layers were placed betweenshell element layers. Now, shell element layers can follow each otherdirectly. Contact definitions have to be done separately.

Allow *PART_STACKED_ELEMENTS to be used in adaptive refinement simulations.

3D tet r-adaptivity now supports *DEFINE_BOX_ADAPTIVE.– For every adaptive part, users can define multiple boxes where different BRMIN & BRMAX (corresponding to RMIN & RMAX in *CONTROL_REMESHING) can be specified for 3D tet remesher to adjust the mesh size.– Current implementation does not support LOCAL option.

Fix bug in 3D adaptivity so that users can now have both non-adaptive tshellparts and 3D adaptive parts in one analysis.

Fix the bug in 3D adaptivity so that users can now have both dummy nodes and3D adaptive parts in one analysis.

A Randles circuit is an equivalent electrical circuit that consists ofan active electrolyte resistance r0 in series with the parallelcombination of the capacitance c10 and an impedance r10.The idea of the distributed Randles model is to use a certain numberof Randles circuits between corresponding nodes on the two currentcollectors of a battery unit cell.These Randles circuits model the electrochemistry that happens inthe electrodes and separator between the current collectors.The EM solver can then solve for the EM fields in the current collectors,and the connections between them.

Added new capability for modeling Randles short, based on *DEFINE_FUNCTIONso that the user has a lot of freedom to define where and whenthe short happens as well as the short resistance.

Added a new capability for battery exothermal reactions alsobased on *DEFINE_FUNCTION. The new keyword *RANDLE_EXOTHERMAL_REACTIONmakes it possible to complement the heating of a short circuit created by a shortby exothermal reactions if, for example, the temperature becomes higher thana threshold value.

End notes for Randles Circuits for Battery Modeling=============================

________________________ Forming Analysis __________

Extend *INCLUDE_AUTO_OFFSET to solid and beam elements (draw beads).

Add a new keyword for springback compensation:*INTERFACE_COMPENSATION_NEW_REFINE_RIGIDto refine and break rigid tool mesh along the user supplied trim curves so compensatedtool mesh follows exactly the blank mesh (file “disp.tmp”). This needs to be done onlyonce in the beginning of the springback compensation (ITER0).

*CONTROL_FORMING_ONESTEP:– Change the default element formulation option for onestep method to QUAD2.– Add a new option QUAD to allow quadrilateral elements to be considered.– Limit the maximum thickening by using a new variable TSCLMAX for the sheet blank.– Set the value of OPTION to a negative value to output the file ‘onestepresult’ in large format (E20.0).– Calculate and add the damage factor and output to the 6th history variable in the output file “onestepresult”. Add the variable for a curve ID to define the fracture strain vs. triaxility. Add another variable DMGEXP (damage parameter), as used in GISSMO model.– Keep the original coordinates for the onestep output “onestepresults”.

Add a new option VECTOR to *CONTROL_FORMING_BESTFIT to output deviation vector(in the format of: NODEID, xdelta, ydelta, zdelta) for each node to its closesttarget element. The deviation vectors are output under the keyword*NODE_TO_TARGET_VECTOR.

*CONTROL_FORMING_OUTPUT:– Output will skip any negative abscissa (Y1) value.– When CIDT<0, the positive value defines the time dependent load curve.

Add a warning in springback compensation *INTERFACE_SPRINGBACK_COMPENSATION toidentify which input file (typically the blank with adaptive mesh not outputdirectly by LS-DYNA) has the wrong adaptive constraints.

*INTERFACE_COMPENSATION_3D: turn off the output of nikin file.

*ELEMENT_LANCING:– Allow some unused lancing curves to be included in the input.– When the gap between the two ends of a lancing curve is not zero, but small enough, then this curve is automatically closed.– Allow several parts to be cut during lancing; the parts can be grouped in *SET_PART_LIST, and defined using a negative value IDPT.– Specify the distance to bottom dead center as AT and ENDT when the new variable CIVD is defined.– Set IREFINE=1 (default) in lancing, to refine blank mesh automatically along the lancing curves.– Re-set the adaptive level to be 1 to prevent those elements along the lancing route to be further refined.– When IREFINE=1, elements along the lancing curve will be refined to make sure that no adapted nodes exist in the neighborhood. This helps get improved lancing boundary.– Change of tolerance for lancing to merge the small elements into bigger ones.

Add a new keyword to perform trimming after lancing (shell elements only):*DEFINE_LANCE_SEED_POINT_COORDINATES. Maximum of two seed nodes can be defined.

Extend *CONTROL_FORMING_TOLERANC to *MAT_036, *MAT_037, *MAT_125, and *MAT_226.When beta is less than -0.5, there is no necking and no calculation of FI.When beta is greater than 1.0, beta=1.0/beta.This keyword adds a smoothing method to calculate the strain ratios for a betterformability index.

Sandwiched parts (*CONTROL_ADAPTIVE, *DEFINE_CURVE_TRIM):– Disable *CONTROL_ADAPTIVE_CURVEs for sandwich parts, since refinement along the curve is automatically done during trimming.– Refine the elements along the trimming curve to make sure no slave nodes are be cut by trimming curves.– Allow mesh adaptivity.– Allow multi-layers of solids.– Add a check to the variable IFSAND in *CONTROL_ADAPTIVE for sandwitch part to be refined to exclude solid elements.

Solid element trimming (*DEFINE_CURVE_TRIM):– Refine those elements along the trimming curve.– Improve solid trimmig to allow the trimming of one panel into two panels with two seed nodes.

Add a new keyword: *CONTROL_FORMING_REMOVE_ADAPTIVE_CONSTRAINTS to removeadaptive constraints on a formed, adapted blank, and replaced them withtriangular elements.

*DEFINE_CURVE_TRIM_NEW:Allow trimming of tshells.

Add a new keyword:*INTERFACE_WELDLINE_DEVELOPMENT to obtain initial weld linefrom the final part and the final weld line position.– When Ioption=-1, convert weld line from its initial position to the final part.– Output the element nodes that intersect the weld line in the final part,and the output file is: affectednd_f.ibo– Output the element nodes that intersect the weld line in the initial part, and the output file is: affectednd_i.ibo

Add a new variable DT0 to *CONTROL_IMPLICIT_FORMING so there is no need touse *CONTROL_IMPLICIT_GENERAL to specify DT0.

*INTERFACE_BLANKSIZE:– Add a new feature DEVELOPMENT option. When ORIENT=2, then a reference mesh file for the formed part should be included. The calculated and compensated boundary will be based on the reference mesh.– Add a new option SCALE_FACTOR that allows the target curve to be moved. This is useful when multiple target curves (e.g. holes) and formed curves are far away from each other.

________________________ *FREQUENCY_DOMAIN ___________________

Added new keyword *CONTROL_FREQUENCY_DOMAIN to define global control parametersfor frequency domain analysis. Currently two parameters are defined:– REFGEO: flag for reference geometry in acoustic eigenvalue analysis (either the original geometry at t=0, or the deformed geometry at the end of transient analysis).– MPN: large mass added per node, to be used in large mass method for enforced motion.

*FREQUENCY_DOMAIN_RESPONSE_SPECTRUM:– Added Von Mises stress output for beam elements in database D3SPCM.– Corrected computation of response spectrum at an intermediate damping value by interpolating spectra at two adjacent damping values. Now the algorithm is based on ASCE 4-98 standard.

*ICFD_CONTROL_FSI:Added a flag which, when turned on will project the nodes of the CFD domainthat are at the FSI interface onto the structural mesh. This is recommendedfor cases with rotation.

*ICFD_CONTROL_MESH:Added a flag to allow the user control over whether there will be re-mesh or not.If there is no re-mesh then we can free space used to backup the mesh and lowermemory consumption.

*ICFD_CONTROL_MESH_MOVE:Added option to force the solver to turn off any mesh displacements. This canbe useful in cases where the mesh is static to save a little bit of calculation time.

*ICFD_CONTROL_OUTPUT:– Added option to support output in Fieldview format, binary and ASCII.– When output of the fluid volume mesh is requested, the mesh will be divided into ten distinct parts, grouping elements in ten deciles based on the mesh quality (Part 1 has the best quality elements, part 10 the worst).

*ICFD_CONTROL_POROUS:Improvements for RTM problems.

*ICFD_CONTROL_TIME:– Added an option to define an initial timestep.– Added an option to shut off the calculation of Navier Stokes after a certain time leaving only the heat equation. This can be useful to save calculation times in conjugate heat transfer cases where the fluid often reaches steady state before the thermal problem.

*ICFD_DATABASE_DRAG:– It is now possible to output the force on segment sets in a FSI run directly in LS-DYNA compatible format. This can be useful for a subsequent linear FSI analysis running only the solid mechanics part.– Added flag to output drag as a surface variable in LSPP.

*ICFD_DATABASE_FLUX:Added option to change output frequency

*ICFD_DATABASE_NODOUT:The user node IDs are now required rather than the internal node IDs

*ICFD_CONTROL_IMPOSED_MOVE:Added the option to choose between imposing the displacements or the velocity.

RANS turbulence models: Standard k-epsilon, realizable k-epsilon, Wilcox k-omegauses HRN laws of the wall by default while SST and Spalart Allmaras use LRN.Improvements on the convergence of all those models.

The DEM particle volume is now taken into account in free surface problems.

Average shear is now output as a surface variable in the d3plots.

*ICFD_CONTROL_MONOLITHIC is obsolete (replaced by *ICFD_CONTROL_GENERAL).

Added more output for the mesh generation indicating the stage of the meshingprocess and the amount of elements that are being generated as a multiple of 10000.Added progress % for the extrusion of the mesh during the BL mesh generation.

Improvements on the element assemble speed in MPP.

Fixed synchronization problem for the last timestep in an FSI problem.

More options have been added to the timer output.

Correction of the calculation of the flux in *ICFD_DATABASE_FLUX in free surface cases.

Enhanced termination process when the implicit solver deterimined an early termination.

When implicit springback was following an explicit transient step, theimplicit keywords with the _SPR were not properly handled. This is nowcorrected.

Added a warning about the combined use of *CONSTRAINED_RIGID_BODY_STOPPERS and thelagrange multiplier formulation for joints (*CONTROL_RIGID) for explicit.The warning recommends switching to the penalty joint formulation.

Applied numerous bug fixes to the implicit solver associated with *CONSTRAINED_INTERPOLATIONwhere there are lots of independent degrees-of-freedom.

*CONTROL_IMPLICIT_ROTATIONAL_DYNAMICS:– The VID of the rotating axis can now be defined by both *DEFINE_VECTOR and *DEFINE_VECTOR_NODES. It enables the movement of the rotating axis. Previously, only *DEFINE_VECTOR could be used to define the VID.– The rotational dynamics now work in MPP.

Shell forms 23 and 24 (high order shells), 1D seatbelts, Hughes-Liu and spotweldbeams (types 1 and 9) are now supported with the implicit accuracy option(IACC=1 in *CONTROL_ACCURACY) to render strong objectivity for large rigid bodyrotations. Also, shell type 16 is supported with implicit accuracy option, resultingin forms 16 and -16 giving the same solution.

Translational and generalized stiffness joints are now strongly objective forimplicit analysis. See CONSTRAINED_JOINT_STIFFNESS….

In implicit it may happen that the initial loads are zero, forinstance in forming problems. In addition, the goal is to movea tool in contact with a workpiece, and the way line searchand convergence works, it is hard to get things going.We now attempt to handle this situation by automatically associating anaugmented load to the prescribed motion simply to get off the ground.

New tolerances on maximum norms are introduced for convergence in implicit:ratio of max displacement/energy/residual, and absolute values of nodal andrigid body translation/rotational residual can be specified.See DNORM.LT.0 on *CONTROL_IMPLICIT_SOLUTION for defining an additional cardfor these parameters DMTOL, EMTOL and RMTOL.Furthermore, maximum absolute tolerances on individual nodal or rigid bodyparameters can be set on NTTOL, NRTOL, RTTOL and RRTOL on the same card.

If ALPHA<0 on first *CONTROL_IMPLICIT_DYNAMICS card, the HHT implicittime integration scheme is activated.

________________________ *INITIAL ___________________

Fix *INITIAL_VELOCITY_GENERATION when used with *INCLUDE_TRANSFORM, whichwas broken due to misplaced conditionals in r100504.

Fix 3 bugs for *INITIAL_VELOCITY_GENERATION involving omega>0 and icid>0:– When nx=-999. Now the directional cosine defined by node NY to node NZ will be the final direction to rotate about. In other words, the direction from node NY to node NZ will not be projected along icid any more.– When nx != -999, (xc,yc,zc) should not be rotated along icid, since (xc,yc,zc) are global coordinates.– When *INITIAL_VELOCITY_GENERATION is included by *INCLUDE_TRANSFORM, (xc,yc,zc) is transformed.

Add the option of ramping time steps, ndtrrg, for *INITIAL_FOAM_REFERENCE_GEOMETRY.The solid elements with reference geometry and ndtrrg>0 will restore its referencegeometry in ndtrrg time steps.

Fix incorrect initial velocity when ICID.ne.0 in *INITIAL_VELOCITY_GENERATION,and rotational velocity, omega, is not zero and *PART_INERTIA is also present.

Fix *INITIAL_STRAIN_SHELL output to dynain for shell types 12 to 15 in 2D analysis.Write out strain at only 1 intg point if INTSTRN=0 in *INTERFACE_SPRINGBACK_LSDYNA andall strains at all 4 intg points if INTSTRN=1 and nip=4 in *SECTION_SHELL.

Skip transformation of the initial velocities if ICID>0 and *INCLUDE_TRANSFORM isused to transform the keyword input file with the *INITIAL_VELOCITY…. keyword.Also echo warning message, KEY+1109, that the transformation will be skippedsince icid is specified.

Fix incorrect transformation of *DEFINE_BOX which results in incorrect initialvelocities if the box is used in *INITIAL_VELOCITY.

Fixed *INITIAL_STRESS_DEPTH when used with 2D plane strain and axisymmetric elements.The prestress was being zeroed.

Improved the precision of the initial deformation calculation for*INITIAL_FOAM_REFERENCE_GEOMETRY in the single precision version.

*ELEMENT_SHELL_NURBS_PATCH:– Isogeometric shell analysis now implemented for SMP with multiple CPUs, including consistency (ncpu<0).– Add a power iteration method to get the maximum eigen-frequency for each isogeometric element. This will be used to set a reasonable time step for trimmed elements.

*ELEMENT_SHELL_NURBS_PATCH:Changed the way of projecting the results from isogeometric (NURBS)elements to the interpolation elements. Now a background mesh, spannedover the locations of the integration points of the isogeometric (NURBS)elements serves as basis to interpolate results from the integrationpoints to the centroid of the interpolation elements. This change maylead to slightly different post-processing results in the interpolationelements.

Add support for trimmed NURBS to work in single precision. Anyway, itis still recommended to use double precision versions for trimmedNURBS patches.

Add post-processing of strains and thickness for interpolation shells.

________________________ *LOAD ___________________

Fixed bugs affecting discrete beam elements (ELFORM=6) when used withstaged construction. Here, “dormant” refers to elements that have notyet become active as defined on *DEFINE_STAGED_CONSTRUCTION_PART.– Dormant discrete beams could still control the timestep and attract mass-scaling, when they should not do so.– Dormant discrete beams reaching a failure criterion defined on the *MAT card were deleted, when they should not be.– The displacements output (see *DATABASE_DISBOUT) included displacements occurring while the elements were dormant. Now, the output displacements are reset to zero at the moment the element becomes active.

Fixed bug in Staged Construction: if FACT on*CONTROL_STAGED_CONSTRUCTION had been left blank, and Dynamic Relaxationwas active, an error termination occurred.

Fix GRAV=1 in *PART which was not were not working correctly with *LOAD_DENSITY_DEPTH.Make *LOAD_DENSITY_DEPTH work for Lagrangian 2D elements.

Fix insufficient memory error,SOL+659, when using *LOAD_ERODING_PART_SET with MPP.

Fix incorrect loading when using *LOAD_ERODING_PART_SET with BOXID defined.

Added *LOAD_SUPERPLASTIC_FORMING for implicit analysis.

*LOAD_SUPERPLASTIC_FORMING box option now works in MPP.

________________________ *MAT and *EOS ______________

*MAT_197 (*MAT_SEISMIC_ISOLATOR) could becomeunstable when the parameter DAMP was left at its default value. A workaroundwas to input DAMP as a small value such as 0.05. The timestepfor *MAT_197 is now smaller than previously, irrespective of the DAMP setting,and the behaviour is now stable even if DAMP is left at the default.

Fixed bug: An error trap was wrongly preventing ELFORM=15 for *MAT_169(*MAT_ARUP_ADHESIVE). Wedge elements with ELFORM=15 are now permitted.

*MAT_172 (*MAT_CONCRETE_EC2):=============================Note that items (1) and (2) below can lead to different resultscompared to previous versions of LS-DYNA.(1) The number of potential cracks in MAT_172 shell elements has been increased from 2 to 4. MAT_172 uses a fixed crack model: once the first crack forms, it remains at the same fixed angle relative to the element axes. Further cracks can then form only at pre-defined angles to the first crack. Previously, only one further crack could form, at 90 degrees to the first crack. Thus, if the loading direction subsequently changed so that the principal tension is at 45 degrees to the first crack, that stress could exceed the user-defined tensile strength by a considerable margin. Now, further cracks may form at 90, +45 and -45 degrees to the first crack. Although the maximum principal stress can still exceed the user-defined tensile strength, the “error” is much reduced. There is an option to revert to the 2-crack model as in R9 (to do this, add 100 to TYPEC).(2) Add element erosion to MAT_172. This change may lead to different results compared to previous versions, because erosion strain limits are now added by default. Elements are now deleted when crack-opening strain becomes very large, or the material is crushed beyond the spalling limit. Plastic strain in the rebar is considered too. Previously, these elements that have passed the point of being able to generate any stress to resist further deformation would remain in the calculation, and sometimes showed very large non-physical deformations and could even cause error terminations. Such elements would now be deleted automatically. Default values are present for the erosion strains but these can be overridden in the input data, see new input fields ERODET, ERODEC, ERODER.(3) New history variables 10,11,12 (maximum value so far of through-thickness shear stress). This is useful for checking results because MAT_172 cracks only in response to in-plane stress; before cracking occurs, the through-thickness shear capacity is unlimited. The data components are: Ex History Variable 10 – maximum out of 11 and 12 Ex History Variable 11 – maximum absolute value of YZ shear stress Ex History Variable 12 – maximum absolute value of ZX shear stress These are in the element local axis system. Note that these variables are written only if TYPESC is zero or omitted. TYPESC is a pre-existing capability that requests a different type of shear check.(4) Fixed bug. Elastic stiffness for MAT_172 beams was not as described in the manual, and the axial response could sometimes become unstable. The bug did not affect shell elements, only beams.(5) *MAT_172 can now handle models with temperatures defined in Kelvin (necessary if the model also has heat transfer by radiation). *MAT_172 has thermally-sensitive material properties hard-wired to assume temperatures in Centigrade. A new input TMPOFF in *MAT_172 offsets the model temperatures before calculating the material properties.(6) When the input parameter AGGSZ is defined, the maximum shear stress that can be transferred across closed cracks is calculated from a formula that has tensile strength and compressive stress as inputs. In MAT_172, the tensile strength of concrete is reduced when compressive damage has occurred (see description of UNLFAC). Up to now, compressive damage was therefore influencing the maximum shear across cracks. However, the Norwegian standard from which the shear forumla is taken treats the tensile strength as a constant. Therefore, for the purpose of calculating the maximum shear stress across closed cracks only, the compressive damage effect is now ignored.(7) Added capability for water pressure in cracks, for offshore applications. The water pressure is calculated from the depth of the element below the water surface (calculated from the z-coordinate). The water pressure is applied as a compressive stress perpendicular to the plane of any crack in the element. See new input fields WRO_G and ZSURF.

*MAT_119 (*MAT__GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM):Fixed bug in UNLOAD option 2. The bug occurs if anunloading curve has been left zero (e.g. LCIDTUR) while the correspondingloading curve was non-zero (e.g. LCIDTR), and UNLOAD=2. Depending on thecomputer system, the symptoms could be harmless or the code could crash.Now, if the unloading curve is left blank, it is assumed to be the same asthe loading curve i.e. load and unload up and down the same curve. Thatbehaviour was already implemented for UNLOAD=1.

Fix inconsistency for *MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY/*MAT_123 when ncpu<0.

Include original volume output to dynain file for 2D analysis when materialswith an equation-of-state are used. This is needed to compute the deformationgradient when initializing a run using the dynain file.

Error terminate with message, KEY+1115, if _STOCHASTIC option is invoked formaterials 10,15,24,81,98, or 123 but no *DEFINE_STOCHASTIC_VARIATION or*DEFINE_HAZ_PROPERTIES keyword is present in the input file.

Fix spurious error termination when using *DEFINE_HAZ_PROPERTIES with adpativity.

Implement scaling of failure strain for *MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY_STOCHASTIC/*MAT_123_STOCHASTIC for shells.

Fix incorrect behavior for *MAT_LINEAR_ELASTIC_DISCRETE_BEAM/*MAT_066 when usingdamping with implicit (static) to explicit switching.

Fixed *MAT_FABRIC/*MAT_034 with the negative unloading curve option. When searchingfor the intersection point of the load and unload curves, and extrapolation of oneof the curves was needed to find the intersection point, the extrapolated stresswas calculated incorrectly causing unpredictable behavior.

Fixed fabric material forms 0 and 1 when used with a reference geometry.There were two problems, both occuring when there are mixed quad and triangularelements in the same block. A flaw in the strain calculation was leading to possibleNaN forces in the elements. When a reference geometry was not used, the forcesfrom trinagular elements in mixed element blocks were 2 times too high.

Added a new option for *MAT_SPOTWELD called FMODE. The FMODE option is available forDMGOPT=10, 11, and 12. When the failure function is reached, and when FMODE>0.0 and<1.0, the value of FMODE will determine if a weld will fail immediately, or will havedamage initiated. The failure function may include axail, shear, bending and torsionterms. If the sum of ths squares of the shear and torsion terms divided by the sum ofthe square of all terms is greater than FMODE, then the weld will fail immediately.Otherwise, damage will be initiated.

Enabled OPT=-1 on *MAT_SPOTWELD for brick elements which had not worked previously.Also, fixed TRUE_T when used with brick element forms 0, 1, and -1.

Fixed spotwelds with DMGOPT=12 by removing warning STR+1327 which madeit impossible to set a small value of RS without triggering this warning,or without setting EFAIL smaller. Setting EFAIL small however could leadto damage initiation by plastic strain when the user wanted only initationby the failure function.

If DMGOPT=10, 11, or 12 and EFAIL=0, on *MAT_SPOTWELD, damage will now initiate onlyby the failure function. If EFAIL>0, then damage will initiate be either thenfailure function or when plastic strain exceeds EFAIL. Prior to this version,amage could initiate when plastic strain exceeds zero if the user set EFAIL=0.This behavior is still true for DMGOPT=0, 1, or 2, but no longer for DMGOPT=10, 11, or 12.

Allow solid spot welds and solid spot weld assemblies to have up to 300 points in therunning average that is used to smooth the failure function. In other words,up to NF=300 is possible.

Fixed a problem with brick spot weld assemblies when OPT=0 failure is used withoutdefining any weld resultant values. Welds were being immediately deleted.

Added new PID option for *DEFINE_SPOTWELD_FAILURE (applies to *MAT_SPOTWELD, OPT=10).Changes the Card 3 input for static strength values to use part set ID’s ratherthan material ID’s.

Modified shell *MAT_214/*MAT_DRY_FABRIC to calculate fiber strains based on thecurrent distance between the points where the fibers intersect with the elementedges. Previously, they were calculated from the rate-of-deformation, but this wasnot as accurate as the new total strain measure.

Fixed unit scaling for GAMAB1 and GAMAB2 on *MAT_DRY_FABRIC. We were incorrectlytransforming them as stress.

Reworked the plastic stress update in *MAT_225/*MAT_VISCOPLASITC_MIXED_HARDENINGto prevent a divide by zero.

Enabled *MAT_ADD_EROSION to be used with beams that have user defined integration.Memory allocation was fixed to prevent memory errors.

Fixed *MAT_106 when used with tshell form 5 or 6. The elasticcontstants used in the assumed strain field were not reasonable.

Fix issue that could have lead to problems using *MAT_054 (or *MAT_058 or*MAT_158) in combination with TFAIL/TSIZE.gt.0.0 and damping.

*MAT_054 – *MAT_ENHANCED_COMPOSITE_DAMAGE:Add possibility to use failure criterion in *MAT_054 for solids in atransversal isotropic manner. It is assumed that the material 1-directionis the main axis and that the behavior in the 2-3 plane is isotropic.This feature is invoked by setting TI=1 in *MAT_054.

*MAT_058 – *MAT_LAMINATED_COMPOSITE_FABRIC:– Bugfix for shear stiffness behavior in *MAT_058 when using a table definition for GAB and only providing stress-strain-curves for positive shear.– Bugfix for strain-rate dependent stiffness behavior in *MAT_058 when using a table definition for EA, EB or GAB under compressive loading.– Add default values for strengths (XT,XC,YT,YC,SC) 1.e+16 for *MAT_058. If no values for the strengths were defined, unpredictable things could have happened.

*MAT_138 – *MAT_COHESIVE_MIXED_MODE:Store total mixed-mode and normal separation (delta_II & delta_I) on historyvariables 1&2 for *MAT_COHESIVE_MIXED_MODE (*MAT_138). This is only forpost-processing and should not lead to any changes in the results.

*MAT_157 – *MAT_ANISOTROPIC_ELASTIC_PLASTIC:– Add Tsai-Hill failure criterion (EXTRA=2).– Allow strain-rate dependent strength values (XT,XC,YT,YC,ZT,ZC,SXY,SYZ,SZX) using *DEFINE_CURVE. This is available for Tsai-Wu (EXTRA=1) and Tsai-Hill.– Fixed bug in using *MAT_157 with IHIS.gt.0 for shells. Thickness strain update d3 was not correct and plasticity algorithm may have failed.– Add additional option to IHIS in *MAT_157 for SHELLs.– Now also the strength values (XT,XC,YT,YC,SXY) may be initialized via *INITIAL_STRESS_SHELL. See variable IHIS and remarks in the User’s Manual for details of initializing various blocks of material parameters.

*MAT_215 – *MAT_4A_MICROMEC:Add new material *MAT_215 that is a micromechanical material model thatdistinguishes between a fiber/inclusion and a matrix material. Thematerial is intended for anisotropic composite materials, especially forshort (SFRT) and long fiber thermoplastics (LFRT). This model is availablefor shells, tshells and solids.

*MAT_225 – *MAT_VISCOPLASTIC_MIXED_HARDENING:Fixed bug in *MAT_225 (*MAT_VISCOPLASTIC_MIXED_HARDENING) when usinga table for LCSS together with kinematic hardening.

*MAT_261 – *MAT_LAMINATED_FRACTURE_DAIMLER_PINHO:*MAT_262 – *MAT_LAMINATED_FRACTURE_DAIMLER_CAMANHO:– Allow table input for fracture toughness values for mats 261/262.. Table represents fracture toughness vs. element length vs. strain rate (shells, tshells, solids)– Fixed bug in mats 261/262 when using *DAMPING_PART_STIFFNESS together with RYLEN=2 in *CONTROL_ENERGY.– Correct shear failure behavior in *MAT_262. This will most probably have no effect to any real application, but could be seen in very special 1-element tests.

Changed storage of history variables for *MAT_249 (*MAT_REINFORCED_THERMOPLASTIC).A new variable POSTV controls which variables are written and at what historyvariable location in d3plot.

*MAT_254 (*MAT_GENERALIZED_PHASE_CHANGE) can now be used with shell elementsand thermal thick shells.

Added flag ‘EZDEF’ to *MAT_249_UDFIBER. In this case the last row of thedeformation gradient is replaced by 0-0-1.

*MAT_ADD_GENERALIZED_DAMAGE now works for solid elements (only shells in R9).

Add optional failure criterion FFCAP to *MAT_100 with OPT = -1 or 0.

Enable *MAT_ADD_COHESIVE to be used in implicit analysis.

Add alternative version of *MAT_280 invoked by new flag on 1st card.It is a physically based damage model with 4 new parameters.

Enable *DEFINE_CONNECTION_PROPERTIES’ option PROPRUL>=2 to be used withspotweld clusters, i.e. not only 1 hex element but several(via *DEFINE_HEX_SPOTWELD_ASSEMBLY or RPBHX>1 on *CONTROL_SPOTWELD_BEAM).

Enable *MAT_ADD_EROSION to be safely used with material modelsthat have more than 119 history variables, for now the new limit is 169(e.g. necessary for *MAT_157 with IHIS=7).

Add Tsai-Wu failure criterion to *MAT_157 for solid and shell elementsinvoked by EXTRA=1 on card 6 and corresponding parameters on cards 8 and 9.

Add viscoelastic option to *MAT_187 (SAMP-1). Rate dependent Young’smodulus and associated settings can be defined on new optional card 5.

*MAT_USER_DEFINED_MATERIAL_MODELS now provides a few more variablesfor cohesive elements, i.e. additional arguments in subroutines umatXXc:temperature, element size, implicit rejection flag,integration point identifier, and total number of integration points.

A modified version of the 3-parameter Barlat model (*MAT_036) is introducedas *MAT_EXTENDED_3-PARAMETER_BARLAT. In this model,hardening in 00, 45, 90, biaxial and shear can be specified as loadcurves. Furthermore, r-values in 00, 45, 90, biaxial and shear can be specifiedin terms of load curves vs plastic strain or constants. This is an extensionof hardening law 7 of the original 3-parameter Barlat model.

Improve implicit version of *MAT_098/*MAT_SIMPLIFIED_JOHNSON_COOK.

*MAT_181/*MAT_SIMPLIFIED_RUBBER/FOAM is now supported for 2D implicit simulations.

Fixed issue in which *MAT_WINFRITH_CONCRETE wrote d3crack data too frequently.

*EOS_JWL now has an AFTERBURN option. This adds afterburn energy to the EOS,where the energy can be added at a constant or linear rate, or can be addedaccording to Miller’s extension.

User-defined materials for Hughes-Liu beams can now be used with implicit analysis bydefining the appropriate tangent modulus in the supplied routine urtanb.

User-defined cohesive materials can now be used with implicit analysis bydefining the appropriate tangent stiffness.

*MODULE for user-defined materials and other user-defined capabilities:– A new command line option “module=filename” is added to load one module file without changing the input deck. It provides back compatibility to input deck without the MODULE keywords.– The system paths defined in LD_LIBRARY_PATH are also included for searching module files for those filenames start with “+”.

*MAT_260B:– Set default values for P’s and G’s in *MAT_260B.– Add a length scale to the fracture limit. The fracture limit strongly depends on the length scale in the measurement.– Add a new fracture criterion to *MAT_260B (Xue and Wierzbicki, Int. J. solids and Structures 46 (2009) 1423-1435). When the option XUE is activated, an additional card is needed, for example: $ ef0 plim q gama m 0.70 925.7 0.970 0.296 2.04

*MAT_037:– Improve *MAT_037 with negative R value in implicit calculation. The modification will allow the implicit method stress calculation to be more accurate.– Add a new option NLP2 to calculate formability index in *MAT_037. The previous method (option NLP_FAILURE) was based on the effective strain method, which assumes that necking happens at one instant. In fact, it might happen over a longer process. The new method calcuates the damage accumulation.

MPP: increase contact release distance for SINGLE_SURFACE contacts in the caseof a node coming into contact with a solid element.The previous interpretation was releasing when the contact penetration was0.5*solid thickness, but now when the node passes below the solid surface by0.5*solid thickness (which is different by the half thickness of the slavematerial, in the case of a shell slave node).

MPP: fix for viscous damping in automatic tiebreak contact.

Implement new bucket sort based extent testing for MPP single surface contact.

Added MPP support for *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_LUBRICATION.

Furthermore, such a region can contain a “local” designation, in whichcase the decomposition of that region will be done in the coordinatesystem local to the include file, not the global system. For example:

would apply the c2r transformation in the coordinate system of theinclude file, which wasn’t previously possible. The local option canbe useful even if there are no such transformations, as the “cubes”that the decomposition uses will be oriented in the coordinate systemof the include file, not the global system.

Furthermore, the following decomposition related keywords nowhave a _LOCAL option, which has the same effect:

For a small restart in MPP, the value of “memory=” (M1) needed for each processor isstored in the dump files. This is the minimum requirement to read back the model info.If the value of “memory2=” (M2) is specified on the command line,the code will take the maxiimum of M1 and M2.

Fix input error during structured input when using *INITIAL_VELOCITY_GENERATIONand *CHANGE_VELOCITY_GENERATION together in a full deck restart.

Fix incorrect full deck restart analysis if initial run was implicit and thefull deck restart run is explicit. This affects MPP only.

Added one SPG control parameter (itb=2) for semi-brittle fracture analysis.In comparison to itb=0 or itb=1, itb=2 is more efficient in modeling thefragmentation and debris in semi-brittle fracture analysis such as impactand penetration in concrete materials.

Fixed a bug related to E.O.S. in SPG.

Removed some temporary memory allocations to improve efficiency.

Changed the sequence of SPG initialization so that all state variables are properlyinitialized.

Subroutines were developed for SPG failure analysis with thermal effects.Both explicit and implicit (diagonal scaled conjugate gradient iterative only) SPGthermal solvers are available in SMP version only. However, thermal effect isapplied only on material properties, which means thermal induced deformation(i.e., thermal strain or thermal expansion) is not currently included.

Modified *MAT_072R3 for SPG method in concrete applications.

Fixed a bug for SPG method in using continuum damage mechanics. (IDAM=0).

Added the “fluid particle algorithm” (itb=1) to SPG method.This algorithm is implemented in R10.0 as an alternative to the (itb=0) optionin previous version to enhance the numerical stability for SPG method.Users are recommended to use this new option for their ductile failure analysis.

Add ITHK flag in *CONTROL_SPH, card 3. If flag is set to 1, the volumeof the SPH particles is used to estimate a node thickness to be employedby contacts. – Affects *AUTOMATIC_NODES_TO_SURFACE and *CONTACT_2D_NODE_TO_SOLID. – The thickness calculated by ITHK=1 is used only if SST or OFFD are set to zero in the contact cards definitions.

Add SOFT=1 option to *CONTACT_2D_NODE_TO_SOLID. This should helpobtain reasonable contact forces in axisymmetric simulations.Default penalty PEN is 0.1 when SOFT=1.

Implemented non-reflecting boundary conditions for SPH using a newkeyword *BOUNDARY_SPH_NON_REFLECTING.

Bug fix for renormalized SPH formulations with symmetry planes. The renormalizationwas slightly incorrect in the vicinity of symmetry planes.

Density smoothing in SPH formulations 15 and 16 is now materialsensitive. The smoothing only occurs over neighbors of the same material.

Resolved an MPP bug in SPH total Lagrangian formulations (FORM=7/8)which was causing strain concentrations at the interfacesbetween CPU zones.

SPH total Lagrangian (FORM=7/8) in SMP was pretty much serial, hence muchslower than forms 0 or 1. SPH with FORM 7 and 8 now scales properly.

Added support for FORMs 0/1 in axisymmetric. Untilnow, renormalization was always active (equivalent to FORM=1)which can be problematic for very large deformations or material fragmentation.

Added a new option IEROD=2 in *CONTROL_SPH in which SPH particles that satisfya failure criterion are totally eactivated and removed from domain interpolation.his is in contrast to IEROD=1 option in whichparticles are partially deactivated and only stress states are set to zero.

Added support of *MAT_ADD_EROSION, including GISSMO and DIEM damage, for SPH particles.

Echo failed SPH particles into d3hsp and messag file.

*DEFINE_SPH_INJECTION:– Changed the method of generating SPH particles. SPH particles will be generated based on the injection volume (injection area*injection velocity*dt)*density from the material model, resulting in more consistent particle masses and particle distribution.– Offset injecting distance inside each cycle so that outlet distance will be consistent for different outlet SPH layers.– Corrected mass output in d3hsp.

________________________ Thermal Solver ____________

Begin Explicit Thermal Solver notes=========================

*CONTROL_EXPLICIT_THERMAL_SOLVER: Implement an explicit thermal solver and adaptit to support multi-material ALE cases.

Modify the thermal solver routines so they returninstead of terminating, so that *CASE works properly.

*MAT_THERMAL_USER_DEFINED: Fixed bug in element numbering for IHVE=1.

Accept load curve input for dtmin, dtmax and dtemp in *CONTROL_THERMAL_TIMESTEP.As usual if a negative integer number is given its absolute value refers to theload curve id.

The temperature results for the virtual nodes of thermal thick shells are nowaccounted for in *LOAD_THERMAL_D3PLOT. For the mechanics-only simulationthermal thick shells have to be activated.

New contact type for thermal solver that models heat transferfrom and to a shell edge onto a surface (*CONTACT_…_THERMAL with ALGO>1):– Shells have to be thermal thick shells.– Shells are on the slave side.– So far only implemented for SMP.– Includes support for quads and triangles.

New keyword *BOUNDARY_THERMAL_WELD_TRAJECTORY for welding of solid orshell structures.– Keyword defines the movement of a heatsource on a nodal path (*SET_NODE).– Orientation given either by vector or with a second node set.– Works for coupled and thermal only analyses.– Allows for thermal dumping.– Different equivalent heat source descriptions available.– Can also be applied to tshells and composite shells.– Weld torch motion can be defined relative to the weld trajectory.

Solid element formulation 18 now supports thermal analysis.

Thermal solver now supports the H8TOH20 option of *ELEMENT_SOLID.This includes support of *INITIAL_TEMPERATURE condition for theextra 12 nodes generated by H8TOH20.

Thermal solver now supports the H8TOH27 option of *ELEMENT_SOLID.

________________________ Miscellaneous ___________________

*INITIAL_LAG_MAPPING: Implement a 3D to 3D lagrangian mapping and map the nodaltemperatures.

*CONTROL_REFINE_SHELL and *CONTROL_REFINE_SOLID: Add a parameter MASTERSET tocall a set of nodes to flag element edges along which new child nodes are constrained.

Fixed bug occurring when a part has non-zero *DAMPING_PART_STIFFNESS,AND is defined using *PART_COMPOSITE, AND the MIDs referenced by thedifferent integration points have different material types.Symptoms could include many types ofunexpected behaviour or error termination, but in other cases itcould be harmless.

*DAMPING_FREQUENCY_RANGE (including _DEFORM option):Improved internal calculation of damping constants such that the level ofdamping more accurately matches the user-input value across the whole of the frequencyrange FLOW to FHIGH. As an example, for CDAMP=0.01, FLOW=1 Hz andFHIGH=30 Hz, the actual damping achieved by the previous algorithm variedbetween 0.008 and 0.012 (different values at different frequencies betweenFLOW and FHIGH), i.e. there wereerrors of up to 20% of the target CDAMP. With the new algoritm, the errorsare reduced to 1% of the target CDAMP.This change will lead to some small differences in resultscompared to previous versions of LS-DYNA. Users wishing to retain the oldmethod for compatibility with previous work can do this by setting IFLG(7th field on Card 1) to 1.

Fixed bug that could cause unpredictable symptoms if Nodal Rigid Bodieswere included in the Part Set referenced by *DAMPING_FREQUENCY_RANGE or*DAMPING_FREQUENCY_RANGE_DEFORM. Now, the _DEFORM option silently ignoresNRBs in the Part Set while *DAMPING_FREQUENCY_RANGE (non _DEFORM option)damps them.

Fixed bug in *PART_COMPOSITE: if a layer had a very small thickness defined,such as 1E-9 times the total thickness, that layer would be assigned aweighting factor of 1 (it should be close to zero).

Fix errors in implementation of *DEFINE_FILTER type CHAIN.

Fix for *INTERFACE_LINKING_LOCAL when LCID is used. During keyword processing,the LCID value was not properly converted to internal numbering.

Switch coordinates in keyword reader to double precision.

Change “Warning” to “Error” for multiply defined materials, boxes,coordinate systems, vectors, and orientation vectors.The check for duplicate section IDs now includes the element type andremains a warning for now, because SPH is still detected as a SOLID.Once that is straightened out, this should be made an error.

Add “TIMESTEP” as a variable for *DEFINE_CURVE_FUNCTION.This variable holds the current simulation time step.

Fix a bug for the case of CODE=5 in *DEFORMABLE_TO_RIGID_AUTOMATIC.(Fields 3 to 8 are now ignored.)

Issue error message and terminate the simulation when illegal ACTIONis used for *DEFINE_TRANSFORM.

Fix a bug that can occur when adaptive elements are defined in a fileincluded by *INCLUDE_TRANSFORM.

Merge *DEFORMABLE_TO_RIGID_AUTOMATIC cards if they use the same switch time.This dependency of results on the order of the cards and also givesbetter performance.

If *SET_PART_OPTION is used, a “group_file” will be created which can be read intoLS-Prepost (Model>Groups>Load) for easy visualization of part sets.

Forces on *RIGIDWALL_GEOMETRIC_CYLINDER can now be subdivided into sectionsfor output to rwforc. This gives a better idea of the force distributionalong the length of the cylinder. See the variable NSEGS.

Added the keywords *DEFINE_PRESSURE_TUBE and *DATABASE_PRTUBE for simulating pressure tubes in pedestrian crash.